EFI Relay Issues

Hi all.
So I have a 95 4wd m/t with the 2.7 3rz. Late last year and early this year, I had to swap engines after the original blew up. Long story short, it now has a very nice JDM 2.7 in it and has been running perfect since I got it in there in late April (I know a lot of JDMs are crap, the first one I got was trash so I ended up getting another that looked like new).

Anyway, yesterday I was doing some maintenance, I rotated the tires and changed the oil filter(I didn’t change oil cause it’s full synthetic and it’s only been around 5k, I wanted to change the filter cause there was probably some dirt/silicon from when I swapped engines). I also washed up the wheels and tires. I got back in the truck, and it cranked but would not start. After some searching, we banged on the EFI relay and it started up. So, I ran to the store, grabbed a new relay, and it started up and ran just like normal. Problem solved!

Well today I went to work, and it started up just perfect. When I went to leave work, it cranked, hesitated for a second, and then cranked up after some sputtering. When I got home, I tried starting it again a few times. Each time it hesitated and sputtered until it fired up. It runs fine when it gets going.

Could it be another issues besides the relay? Why would replacing the relay fix the problem but then start doing the same thing? Truck does have 315k on it.

 

Any chance a fuel injection circuit ground is located where you were doing the relay work?

Your problem sounds like a ground issue. There are several grounds that need to be clamped corrosion free in order for the engine to run proper.

 

What would that ground look like? I’m going to go over this tomorrow morning and check for grounds and look over the wiring. Could it possibly be the progs that the relay plugs into? It was dark when I put it in so I didn’t look to see the condition of those

 

Does the fuel line lose pressure quickly when you stop the engine? It sounds like it is doesn't have proper fuel pressure when cranking after sitting.

 

Ok, so after looking over it this morning, I found a rag in a bunch of chewed up pieces in the air box in front of the filter. I figured out what it was - I keep a rag tied to the master cylinder, so when I check oil/fluids I can wipe it off. Apparently, I guess mice or something chewed it up and took it over to the air box. I’m running a deck plate mod, so they could have just went right inside the box. It’s in front of the filter, so it’s not inside the actual intake, but still blocking air flow.
I feel like this could definitely be a cause of the rough start, and the relays and connections all seem to look good. It started up several times perfectly this morning.

 

Ok so I now it starts and runs fine but I am getting p1300 and p0100. I did pull the MAF out to check it so maybe that caused the 0100, but this is a 3rz engine with distributor, so how could 1300 throw when it is for the number 1 coil?